FEM3D
Files Describing a 3D Finite Element Model
FEM3D
is a data directory which
contains examples of 3D FEM files, which define a 3D finite element model.
The FEM format is a simple dataset of several files that
can be used to describe a finite element model.
The finite element model might include the following files:

a node file, node coordinates (in 1D, 2D or 3D);

an element file, elements defined by a sequence of node indices.
For this simple format, we assume the elements are all of the same
order, and the most common choices are linear or quadratic tetrahedrons;

a value file, listing the values of one or more functions
at each node.

a boundary node mask file, listing for each node the value
1 if it is a boundary node, and 0 otherwise.

a boundary node file, listing the coordinates of nodes that
lie on the boundary.

a boundary element file, listing the indices (from the
boundary node file) of the nodes that form elements (of one dimension
lower) lying on the boundary of the mesh.
FEM File Characteristics:

ASCII

Each line is one "record"

Each record is either a comment record or a data record;

Comment records begin with the "#" character;

A data record records node coordinates for one node, or
the node indices for one element, or the set of node data
for one node;

For a given file, each data record contains the same number
of items, separated by blanks.
Licensing:
The computer code and data files described and made available on this web page
are distributed under
the GNU LGPL license.
Related Data and Programs:
FEM1D,
a data directory which
contains examples of 1D FEM files,
text files that describe a 1D finite element model;
FEM2D,
a data directory which
contains examples of 2D FEM files,
text files that describe a 2D finite element geometry;
FEM3D_PACK,
a C++ library which
contains utilities for 3D finite element calculations.
FEM3D_PROJECT,
a C++ program which
projects a function F(X,Y,Z), given as a data, into a given finite element space
of piecewise linear tetrahedral elements.
FEM3D_SAMPLE,
a FORTRAN90 program which
evaluates a finite element function defined on 3D tetrahedral mesh.
Reference:

Hans Rudolf Schwarz,
Methode der Finiten Elemente,
Teubner Studienbuecher, 1980,
ISBN: 3519023490.

Gilbert Strang, George Fix,
An Analysis of the Finite Element Method,
Cambridge, 1973,
ISBN: 096140888X,
LC: TA335.S77.

Olgierd Zienkiewicz,
The Finite Element Method,
Sixth Edition,
ButterworthHeinemann, 2005,
ISBN: 0750663200,
LC: TA640.2.Z54.
Sample Files:
BLOCK is 3D FEM data for the function
f(x,y,z)=x^2+2*y^2z^2, on a 5x5x5 grid
of 125 nodes in the cube [0,4]x[0,4]x[0,4], organized into
384 linear tetrahedrons.
CASE1 is 3D FEM data for a 5x1x1 rectangular channel region
using 8261 nodes and 5000 quadratic (ten node) tetrahedral elements.

case1_nodes.txt,
defines the nodes.

case1_elements.txt,
defines the elements.

case1_values.txt,
defines the nodal values U, V, W, and P (three velocity
components and pressure).

case1_boundary_node_mask.txt,
0 for interior nodes, 1 for boundary nodes.

case1_boundary_nodes.txt,
defines the boundary nodes.

case1_boundary_elements.txt,
defines the boundary faces.
CUBE is 3D FEM data for the unit cube,
using 8 nodes, organized into 6 linear tetrahedrons.
P01 is 3D FEM data for a rectangular channel of dimensions
3x1x1 physical units, using 584 nodes and 2568 tetrahedral elements.
P04 is 3D FEM data for a sphere,
using 587 nodes and 2775 linear tetrahedral elements.
You can go up one level to
the DATA directory.
Last revised on 21 December 2010.